1. Field of the Invention
This invention relates to a medical locating apparatus, particularly to a medical locating apparatus which can suitably be used in brain surgery.
2. BACKGROUND OF THE RELATED ART
As CT scanners and MRI scanners are becoming very popular, neurosurgery has encountered a turning point. Namely, the conventional diagnostic imaging such as cranial plain roentgenography and cerebral angiography are now predominantly being replaced by the three-dimensional diagnostic imaging based on computerized analysis data in the field of brain surgery.
In order to reproduce such locational information specified on the image of CT scanning and the like, a medical locating apparatus which locates the site which needs surgical operation, as disclosed, for example, in Japanese Provisional Patent Publication No. 327/1987, is employed. The medical locating apparatus of the disclosure consists of a plurality of arms provided on a bed, a plurality of potentiometers disposed to the joints of the respective arms and an indicating unit disposed at the tip of the arm, by which the site to be operated is detected based on the signal from the potentiometers.
However, since the arms in such conventional medical locating unit are designed to be moved via the respective joints, clutch means must be provided on all of the joints so as to stop the entire locating apparatus. To dispose a heavy clutch means at a high position near the indicating unit is not preferred in view of operability and stability of the locating apparatus.
Meanwhile, since the angles of the respective joints are detected by the potentiometers, the apparatus are not only required to have an A/D converter but also readily affected by the temperature change.
Further, since the weight of each arm is not well-balanced, operation of the arms requires a great operating physical force, presenting poor operability, disadvantageously.